Electric striking mechanism for time pieces

ABSTRACT

An electric striking mechanism for clocks and the like including an electromagnet, a sounding body, a striking mechanism responsive to the electromagnet for striking the sounding body, a circuit for supplying an impulse current to the electromagnet and a control responsive to the electromagnet for controlling the circuit.

United States Patent Ganter et al. 1 Sept. 5, 1972 [541 ELECTRIC STRIKING MECHANISM [56] References Cited FOR TIME PIECES UNITED STATES PATENTS gangG m Sh be -s1- [72] Invemms 231 ,;1 2,972,138 2/1961 Rinker ..340/403 x of Gemany 3,154,911 11/1964 Tschudin ..58/38 3,091,076 5/1963 Reich ..58/38 [73] Assignee: Gebruder Ju g a G 3,407,402 10/1968 Morrison et al. ..340/392 Schramberg/Wuxttemberg, Germany w 3 Primary Examiner-John W. Caldwell [22] Flled' 1970 Assistant Examiner-William M. Wannisky [21] Appl. No.: 66,287 Attorney-Bums, Doane, Swecker & Mathis [30] Foreign Application Priority Data [57] ABS I CT An electric striking mechanism for clocks and the like Sept 1969 Germany 19 46 3413 including an electromagnet, a sounding body, a striking mechanism responsive to the electromagnet for [52] US. Cl. ..340/392, 340/396, 3405/2230; striking the sounding body, a circuit for supplying an impulse current to the electromagnet and a control [51] Int. Cl ..Gl0k l/065 res nsive to the electrom t for comr th 58 Field of Search ..340/392, 400, 396, 401, 403, Cir? agne 1 g e SClaims, 10 Drawing Figures LL20 15 L1 L0 a I I PATENTED SEP 51912 3.689.919 sum 2- ar 3 INVENTORS WOLFGANG GANTER GEOZG KUNZ ELECTRIC STRIKING MECHANISM FOR TIME PIECES BACKGROUND OF THE INVENTION mechanism.

' The invention is based on the task of creating a fully electric striking mechanism which is simple in its structure and which is suitable particularly for electricbattery timepieces. The invention is characterized by the fact that an electric impulse producing circuit has been provided for feeding the electromagnet and in that the device for. controlling the impulse producing circuit is driven by the electromagnet.

Preferably, the striking hammer is a striker passing through the electromagnet. At the same time, a spring has preferably been provided which, whenever the electromagnet is not energized, will hold the striker in a rest position. Upon energization of the electromagnet, the striker will be lifted and in the case of deenergization, the striker will drop under the force of gravity against a sounding'body, for example, a bell.

A housing, preferably made from plastic, receives the parts of the striking mechanism and is overlapped on one side by a sounding body and on the other side is closed by a cover plate. At the same time, the cover plate is preferably equipped with a printed circuit, and

carries the switching elements of the electric impulse producing circuit. The cover plate can be provided with electric contact elements that have been guided out. As the result, it is possible to add the striking mechanism to various clockwork mechanisms in a simple manner.

An astable multivibrator can be provided as electric impulse producingcircuit. It is also possible to provide a contact as an electric impulse producing circuit operated by the electromagnet and which controls the energization of said magnet. Preferably, the impulse producing circuit precedes a control stage, whereby a switching equipment operated by the clockwork mechanism has been provided to keep a capacitor connected to the voltage source in its rest position, but

switched into the input circuit of the control stage at the time of alarm.

The control equipment for the impulse producing circuit may comprise a step-by-step mechanism driven by the striking hammer or by a part connected with said hammer, and a contact arrangement operated by the step-by-step mechanism. The step-by-step mechanism may contain a stepping wheel shifted by a shifting fork in turn operated by the striking hammer, whereby the stepping wheel is provided with cams which operate a contact influencing the impulse producing circuit. The output of the control stage may be bridgeable by means of the contact operated by the stepping wheel. For alignment of the hands of the clock and of the sequence of strokes, a contact may be provided which can be operated at will manually, and which is not parallel to the contact operated by the stepping wheel. Also, a handle may be provided which is accessible from outside of the clockwork mechanism with which the switching arrangement operated by the clockwork mechanism is operable at will.

I The contact operated arbitrarily'by hand may be developed as a change over contact and can be connected in such a way that it short circuits in its rest position a capacitor applied to voltage on the one hand, and in its operating position, connects said capacitor to the impulse producing circuit, the capacitor being dimensioned in such a way that one single impulse will be produced. The contact which can be operated ar bitrarily by hand, however, can also be developed as an operating contact which in its operating position connects a capacitor, bridged by a discharge resistor and connected withv voltage on the one hand, with the impulse producing circuit, the capacitor being dimensioned in such a way that it will produce only one impulse.

The invention will be explained in more detail in the following paragraphs on the basis of the drawing and of a few designs given by way of example.

THE DRAWINGS FIG. 1 is a.bottom plan view of a striking mechanism according to the invention in the form of a unit that can be added, with a view of the cover plate, with individual parts broken away;

FIG. 2 is a section in elevation taken along the lines IIII of FIG.1;

FIG. 3 is a section in elevation taken along the lines III-III of FIG.1;

FIG. 4 is a partial end view of the control contact of FIG. 1;

FIG. 5 is a section in elevation taken along the lines VV of FIG. 1;

FIG. 6 is a top plan view of the striking mechanism of FIG. 1, with a view of the bell, with individual parts of THE DETAILED DESCRIPTION In FIGS. 1-6, 10 designates a housing which may effectively be ejection molded from plastic. This housing 10 has a depression in which an electromagnet 16 has been inserted. This electromagnet 16 is held in the depression 10a by means of holding devices 14 and 15. The electromagnet 16 has a winding 20 and a central bore in which the striker 21 has been slidably mounted. The striker 21 consists of ferromagnetic material, to which a non-magnetic element 17 has been attached. In order to avoid a sticking of the ferromagnetic striker 21, bearing bushings 22 of non-magnetic material have been provided.

Effectively, the electromagnet is arranged with the striker 21 in the position shown in FIG. 1, so that the striker 21 may strike against the bell 12 under the effect of gravity after it has been lifted from the rest position shown in FIG. 1 into the position shown in a dashdot line by the energization of the winding 20 of the magnet 16. The striker 21 is biased in its rest position by a spring 18.

The striker 21 is provided at its non-magnetic end 17 with a disk 19 which cooperates with a spring 2311. This spring 23b is part of a spring 23, the other part 23a of which fits againstpart of the housing and thus serves as a return spring for a shift fork 26 pivotably mountedat point 27. This shift fork 26 is equipped with pegs 260 which cooperate with the stepping wheel 28 to shift the latter. In the case of every lifting movement of the striker 21, theshift fork 26 is moved back and forth as the result of which the stepping wheel 28 is rotated further by one tooth pitch. The stepping wheel 28 can, for example, be injection molded from plastic. As can be seen from FIG. 1, the wheel 28 contains several cams which operate as shifting contact 29, 30. Depending on the desired number of strikes, the cams have different lengths. In order to assure a faultless mounting of the shift fork 26 and of the stepping wheel 28, a bed plate 25 has been provided and has been riveted or welded at point 24 with the help of plastic pegs to the plastic housing 10.

The housing is closed with the help of the cover plate 11. This cover plate 1 1 preferably carries the various switching elements for the electric impulse producing circuit and may effectively be provided with a printed circuit. At the same time, as can be seen from FIG. 1, slots 11b can be provided in the cover plate 11 into the area of which the conducting layers of the printed circuits project so that the entire construction unit can be added, for example, to a clockwork mechanism, whereby at the same time the various contacts are established.

The contacts 29 and 30 are adjustable with the help of cams 31 to 33, as the result of which a precise adjustment of the contact pressure and of the position of the contact 30 is possible in relation to the stepping wheel 28.

FIG. 7 shows one design of an electric impulse ment 42c is established. As the result of that, the charged capacitor C is switched into the input circle of the control transistor T which thereupon becomes conductive and thus connects the astable multivibrator with the minus pole of the battery B. The capacitor C is discharged via the emitter junction of the transistor T so that the transistor T again becomes non-conductive after-a certain time. Thecapacitor C and possibly a resistor switched in series with it should be dimensioned in such a way that only a single impulse through the winding 20 is produced by the multivibrator during the conductive stage of the transistor T Through the impulse energizing the coil 20 of the electromagnet 16, the striker 21 and with it the part 17 with the disk 19 is lifted up and into the position shown in FIG. 1 in a dash-dot line. As the result of that, the shift fork is swivelled via the spring 23b in a counterclockwise direction, as the result of which the stepping wheel 28 is rotated further by one-half tooth pitch.

vAfter termination of the current impulse, the striker 21 drops off and strikes against the bell l2. Simultaneously, the shift fork26 is swivelled in a clockwise direction by meansv of the spring arm 23a, as the result of which the stepping wheel 28 is again rotated further by one-half tooth pitch. If the stepping wheel, for example, prior to the occurrence of the current impulse, has been in the position shown in FIG. 1, then the stepping wheel is rotated by one tooth pitch further during the one energizing impulse where the contacts 29 and 30 (FIG. 1), which correspond to the contact 43 in FIG. 1,

producing circuit. Two separate arrangements bordered by a dash-dot line are shown. The left-hand part of the RC section C,R This multivibrator produces impulses with a frequency of about 0.5 Hertz. In the output circuit of the transistor T is the winding 20 of the electromagnet 16 driving the striking hammer 21. A control stage T precedes the multivibrator at the input circuit of which a capacitor C is in series with the changeover contact 42 of the clockwork mechanism. The changeover contact is operated by a cam 41 arranged on the minute tube or the minute shaft 40.

As can be seen from the circuit, the capacitor C is charged in the position of the changeover contact shown via the preliminary resistance R, and the contact elements 42a, 42b from the battery B. On the hour, the contact element 42b is lifted by the cam 41 as the result of which the connection with the contact element 42a is interrupted and a connection with the contact eleare not closed since no cam is available in this area to lift the contact 30. Therefore, only a single stroke has been carried out.

If the stepping wheel 28 is in such a position in relation to the contact 30', that after the occurrence of the first current impulse the contact 30 is lifted by one of the cams, then the contact 43 of FIG. 7 is closed and the transistor T is bridged on the output side so that even after discharge of the capacitor C the multivibrator remains connected with the voltage source B. Further current impulses are produced by the multivibrator until the contact 30 drops off the pertinent cam to again open the contact 43 in FIG. 7 as the result of which the battery B is removed from the multivibra tor.

The circuit arrangement according to FIG. 8 corresponds partly to that according to FIG. 7. However, in this instance, no multivibrator has been provided and a contact 45, operated by the electromagnet 16 with its energizing winding 20, serves for the production of an impulse. If in the case of this circuit arrangement, the changeover contact 42 is operated by the cam 41, then the previously charged capacitor C is switched into the input circuit of the transistor T, which on its output side feeds the winding 20 directly. Through the operation of the electromagnet 16 with its winding 20, the contact 45 is closed and thus the emitter junction of the transistor T is shortcircuited. The electromagnet with its winding 20 will thereupon be deenergized again, unless the contacts 29 and 30 which correspond to the contact 43 in FIG. 8 have been closed through the movement of the stepping wheel 28, in which casethe transistor T is modulated further at resistor R The changeover contact 42 is made in practice effectively as a snap-action switch of a known type. The

changeover contact42 will then only remain for a brief time in the changeover position and is subsequently returned again promptly into the rest position shown.

There is a contact 44 operable manually in parallel to the contact 43, which makes possible an adjustment of the sequence of strikes with the position of the hands. If the switch 44 is operated, the multivibr ator is connected with the battery B and the winding 20 is energized by impulses independently of the position of the hands. As the result, the stepping wheel 28 can be brought into the position for the following striking of the hour. The switch 44 at the same time only needs to be operated for a brief time since otherwise it would be possible for the next programmed sequence to take its course unintentionally. In order to make sure about this, the designs shown in FIGS. 9 and 10 can be used.

FIG. 9 shows a changeover contact 44a which short circuits a capacitor C attached unilaterally to the battery in its rest position and connected with the feed line to the multivibrator during operation. Asthe result, a current impulse is fed to the multivibrator independently of the fact of how long the key 44a has been depressed.

In the caseof the design according to FIG. 10, the capacitor C likewise has been provided which can be connected with the feed line of the multivibrator with the help of the movement contact 44b. After opening of the switch 44b, the capacitor C is again discharged via the resistor R I The same effect may also be achieved with the help of the handle 46, drawn in a broken line into FIGS. 7 and 8, which can be operated independently of the position of the hands.

The striking mechanism according to the invention is an independent aggregate, which can be assigned to an electric clockwork mechanism of any design, whereby only electric wire connections are needed between the clockwork mechanism and the added constructional element.

What is claimed is:

1. Apparatus comprising;

an electromagnet;

a sounding body;

striking means responsive to said electromagnet for striking said sounding body;

circuit means for. supplying an impulse of current to said electromagnet, including, a dc. source, a capacitor, an electronic valve, and

a capacitor, an e ectromc valve, and

first switch means adapted to be responsive to a clock mechanism for selectively connecting said capacitor with said electronic valve; and

control means responsiveto said electromagnet for controlling said circuit means, including a stepping mechanism rotated a predetermined increment responsively to the energization of said electromagnet including,

a wheel and cam means carried by said wheel, said wheel being rotated responsively to said armature and,

second switch means operated responsively to said stepping mechanism.

3. The apparatus of claim 2 wherein said electronic valve includes a transistor;

wherein said second switch means is operable to directly connect the collector and emitter electrodes of said'transistor; and

including manually operable switch means bridging said second switch means.

4. The apparatus of claim 3 including a housing for said electromagnet and said control means, said housing being enclosed on one side by said sounding body and enclosed on the other side by a cover plate, said circuit means being carried by said cover plate;

first switch means adapted to be responsive to the operation of a clock; and

means operable externally of said housing for manually operating said first switch means.

5, The apparatus of claim 4 wherein said externally operable means includes means for producing a single current impulse. 

1. Apparatus comprising: an electromagnet; a sounding body; striking means responsive to said electromagnet for striking said sounding body; circuit means for supplying an impulse of current to said electromagnet, including, a d.c. source, a capacitor, an electronic valve, and first switch means adapted to be responsive to a clock mechanism for selectively connecting said capacitor with said electronic valve; and control means responsive to said electromagnet for controlling said circuit means.
 2. Apparatus comprising: an electromagnet; a sounding body; striking means responsive to said electromagnet for striking said sounding body, including an armature axially disposed within said electromagnet; circuit means for supplying an impulse of current to said electromagnet, including, a d.c. source, a capacitor, an electronic valve, and first switch means adapted to be responsive to a clock mechanism for selectively connecting said capacitor with said electronic valve; and control means responsive to said electromagnet for controlling said circuit means, including a stepping mechanism rotated a predetermined increment responsively to the energization of said electromagnet including, a wheel and cam means carried by said wheel, said wheel being rotated responsively to said armature and, second switch means operated responsively to said stepping mechanism.
 3. The apparatus of claim 2 wherein said electronic valve includes a transistor; wherein said second switch means is operable to directly connect the collector and emitter electrodes of said transistor; and including manually operable switch means bridging said second switch means.
 4. The apparatus of claim 3 including a housing for said electromagnet and said control means, said housing being enclosed on one side by said sounding body and enclosed on the other side by a cover plate, said circuit means being carried by said cover plate; first switch means adapted to be responsive to the operation of a clock; and means operable externally of said housing for manually operating said first switch means.
 5. The apparatus of claim 4 wherein said externally operable means includes means for producing a single current impulse. 